JP6582543B2 - Anomaly detection device - Google Patents

Description

  The present invention relates to an abnormality detection device that detects an abnormality that has occurred in a device that detects the traveling speed of a vehicle.

  Automobiles, including large trucks, are obligated to set limits on the speed at which they can travel, and it is necessary to accurately measure the vehicle's travel speed (hereinafter sometimes referred to as “vehicle speed”). Yes. Patent Document 1 discloses a method for detecting that an abnormality has occurred in a vehicle speed sensor that measures the traveling speed of a vehicle in order to prevent the vehicle speed from being erroneously detected due to a failure of a vehicle speed sensor that measures the vehicle speed. Yes.

JP-A-61-245061

  In the conventional method, it is determined whether or not the vehicle is in the running state based on the gear state, the clutch state, and the engine speed, and the vehicle speed is equal to or lower than the predetermined value despite the running state. It was determined that an abnormality occurred in the vehicle speed sensor. However, when determining whether or not the vehicle is traveling based on the state of the gear, the state of the clutch, and the number of revolutions of the engine, an apparatus that extracts the power for driving the bodywork of the specially equipped vehicle such as a truck from the traveling engine. When a certain PTO (Power Take Off) is operated, it may be determined that the vehicle is traveling even though it is not traveling. As a result, there is a problem that it is erroneously determined that an abnormality has occurred even though no abnormality has occurred in the vehicle speed sensor.

  Accordingly, an object of the present invention is to improve the accuracy of detecting an abnormality that has occurred in a device that detects the traveling speed of a vehicle.

  The abnormality detection device of the present invention acquires engine information acquisition means for acquiring rotation speed information indicating the rotation speed of the engine, gear information acquisition means for acquiring gear information indicating the gear state, and clutch information indicating the clutch state. Clutch information acquisition means, PTO information acquisition means for acquiring PTO information indicating the operating state of the PTO that is a device for taking out the power of the engine, speed detection means for detecting the traveling speed of the vehicle, the rotational speed, the gear The speed detection means when the state, the clutch state, and the PTO state indicate a running state in which the vehicle is running and the traveling speed detected by the speed detecting means is equal to or less than a predetermined threshold. And determining means for determining that an abnormality has occurred.

  With such a configuration, even when the abnormality detection device can be determined to be in the running state based on the gear state, the clutch state, and the engine speed, when the PTO is operating, Since it can be determined that the vehicle is not in the traveling state, the accuracy of determining the occurrence of abnormality in the speed detection means can be improved.

  Until the determination means detects that the clutch state has changed, the rotational speed, the gear state, and the PTO state indicate the traveling state, and the traveling speed detected by the speed detecting unit is When it is determined that an abnormality has occurred in the speed detection means when it is less than or equal to a predetermined threshold and the clutch state has been changed, the rotational speed, the gear state, the clutch state, and the PTO state are When the traveling state is indicated and the traveling speed detected by the speed detecting unit is equal to or less than a predetermined threshold, it may be determined that an abnormality has occurred in the speed detecting unit.

  With such a configuration, the abnormality detection device can correctly determine whether or not an abnormality has occurred in the speed detection means even when the clutch switch indicating the state of the clutch has failed, After confirming that the clutch switch has not failed, it is possible to correctly detect that an abnormality has occurred using the state of the clutch switch.

  The engine information acquisition means further acquires an accelerator opening and a fuel injection amount, and the determination means travels in which the accelerator opening is equal to or greater than a predetermined value and the fuel injection amount corresponds to the rotation speed. If the traveling speed detected by the speed detection means is equal to or lower than a predetermined threshold value, although the fuel injection amount is equal to or greater than the lower limit amount in the state, it may be determined that an abnormality has occurred in the speed detection means. With such a configuration, even when the clutch switch or the neutral switch indicating the state of the gear is out of order, the abnormality detection device can correctly determine whether or not an abnormality has occurred in the speed detection means. .

  The determination means stores that the condition that the accelerator opening is equal to or larger than a predetermined value and the fuel injection amount is equal to or larger than a lower limit amount corresponding to a load in a traveling state corresponding to the rotation speed is satisfied. It may be stored in the part. With such a configuration, the abnormality detection device can correctly determine whether or not the vehicle is in a traveling state even when it is released in a short time after the accelerator pedal is depressed. The detection accuracy of the occurrence of abnormality can be improved.

  According to the present invention, it is possible to improve the accuracy of detecting an abnormality that has occurred in a device that detects the traveling speed of a vehicle.

It is a figure which shows the structure of the abnormality detection apparatus which concerns on 1st Embodiment. It is a flowchart which shows the procedure of the determination process which a determination part performs. It is a flowchart which shows the procedure of the determination process which the determination part in the abnormality detection apparatus which concerns on 2nd Embodiment performs.

<First Embodiment>
[Configuration of Abnormality Detection Device 1]
FIG. 1 is a diagram illustrating a configuration of an abnormality detection apparatus 1 according to the first embodiment. The abnormality detection device 1 is connected to an engine control unit 2, a neutral switch 3, a clutch switch 4, a PTO switch 5, and a vehicle speed sensor 6. The abnormality detection device 1 detects that an abnormality has occurred in the speed detection means based on information acquired from the engine control unit 2, the neutral switch 3, the clutch switch 4, the PTO switch 5, and the vehicle speed sensor 6, and the detection result On the display in the instrument panel. The speed detection means includes wiring for connecting the vehicle speed sensor 6 and the abnormality detection device 1, and the vehicle speed sensor 6.

The engine control unit 2 controls the accelerator opening and the fuel injection amount to operate the engine. The engine control unit 2 notifies the abnormality detection device 1 of information indicating the engine speed.
The neutral switch 3 is a switch that changes between an on state and an off state depending on whether or not the gear is in a neutral state. The neutral switch 3 in the present embodiment is turned off when the gear is engaged, and is turned on when the gear is not engaged.

  The clutch switch 4 is a switch that changes between an on state and an off state depending on whether or not the clutch is in a connected state. The clutch switch 4 in the present embodiment is turned off when the clutch is connected, and turned on when the clutch is released.

  The PTO switch 5 is a switch that changes between an on state and an off state depending on whether or not the PTO is operating. The PTO switch 5 in the present embodiment is turned on when the PTO is operating, and is turned off when the PTO is not operating. In the case of a vehicle in which the PTO does not operate unless the parking brake is applied, whether the parking brake is applied is equivalent to whether the PTO is operating. Therefore, the PTO switch 5 may be a switch that changes between an on state and an off state in conjunction with the parking brake state.

  The vehicle speed sensor 6 outputs a pulse signal according to the rotation of the wheel. The vehicle speed sensor 6 outputs a number of pulse signals proportional to the rotational speed of the wheels within a unit time.

Hereinafter, the configuration of the abnormality detection apparatus 1 will be described in detail. The abnormality detection device 1 includes a storage unit 11 and a control unit 12.
The storage unit 11 includes a ROM (Read Only Memory) and a RAM (Random Access Memory). The storage unit 11 stores a program executed by the control unit 12. The storage unit 11 also includes various threshold values used for determining whether or not an abnormality has occurred in the speed detection means, a neutral switch flag indicating whether or not the neutral switch 3 is operating normally, and a clutch switch 4. A clutch switch flag indicating whether or not the PTO switch 5 is operating normally and a PTO switch flag indicating whether or not the PTO switch 5 is operating normally are stored. The storage unit 11 stores information indicating the relationship between the number of pulse signals per unit time output from the vehicle speed sensor 6 and the traveling speed of the vehicle.

  The control unit 12 is, for example, a CPU (Central Processing Unit). The control unit 12 executes the program stored in the storage unit 11 to thereby execute an engine information acquisition unit 121, a gear information acquisition unit 122, a clutch information acquisition unit 123, a PTO information acquisition unit 124, a speed detection unit 125, and a determination unit. It operates as 126.

  The engine information acquisition unit 121 acquires various types of information related to the state of the engine from the engine control unit 2. For example, the engine information acquisition unit 121 acquires rotation number information indicating the rotation number of the engine, and notifies the determination unit 126 of the rotation number information.

  The gear information acquisition unit 122 acquires gear information indicating a gear state indicating whether or not the gear is in the neutral state from the neutral switch 3 and notifies the determination unit 126 of the acquired gear information. When the gear information acquisition unit 122 detects a change from the neutral state to the geared state, the gear information acquisition unit 122 stores information indicating that the neutral switch 3 is operating normally in the storage unit 11. For example, the gear information acquisition unit 122 changes the value of the neutral switch flag stored in the storage unit 11 from 0 to 1.

  The clutch information acquisition unit 123 acquires clutch information indicating a clutch state indicating whether or not the clutch is connected from the clutch switch 4 and notifies the determination unit 126 of the acquired clutch information. When the clutch information acquisition unit 123 detects that the clutch has changed from the released state to the connected state, the clutch information acquisition unit 123 stores information indicating that the clutch switch 4 is operating normally in the storage unit 11. . For example, the clutch information acquisition unit 123 changes the value of the clutch switch flag stored in the storage unit 11 from 0 to 1.

  The PTO information acquisition unit 124 acquires PTO information indicating the state of the PTO such as whether or not the PTO is in operation from the PTO switch 5 and notifies the determination unit 126 of the acquired PTO information. When detecting that the operation state of the PTO has changed, the PTO information acquisition unit 124 causes the storage unit 11 to store information indicating that the PTO switch 5 is operating normally. For example, the PTO information acquisition unit 124 changes the value of the PTO switch flag stored in the storage unit 11 from 0 to 1.

  The speed detection unit 125 acquires a pulse signal indicating the number of rotations of the wheel per unit time from the vehicle speed sensor 6, and detects the traveling speed of the vehicle based on the acquired pulse signal. Specifically, the speed detection unit 125 reads out information indicating the relationship between the number of pulse signals per unit time and the travel speed from the storage unit 11, so that the travel speed corresponding to the number of pulses acquired from the vehicle speed sensor 6. Is identified. The speed detection unit 125 notifies the determination unit 126 of the identified travel speed.

  The determination unit 126 includes the rotation speed information acquired by the engine information acquisition unit 121, the gear information acquired by the gear information acquisition unit 122, the clutch information acquired by the clutch information acquisition unit 123, the PTO information acquired by the PTO information acquisition unit 124, Based on the traveling speed detected by the speed detector 125, it is determined whether or not an abnormality has occurred in the speed detecting means. Specifically, in the determination unit 126, first, the rotational speed information indicates a rotational speed that is equal to or higher than the lower limit value of the rotational speed in the traveling state, the gear information indicates a state in which the gear is engaged, and the clutch information Indicates a state in which the clutch is engaged, and when the PTO information indicates a state in which the PTO is not operating, it is determined that the vehicle is in a traveling state. Then, the determination unit 126 determines that an abnormality has occurred in the speed detection means when the traveling speed detected by the speed detection unit 125 is equal to or less than a predetermined threshold despite the traveling state.

  The determination unit 126 uses information obtained based on switches other than the switch that has not detected the change until it is detected that all of the neutral switch 3, the clutch switch 4, and the PTO switch 5 have changed. Thus, it may be determined whether or not the vehicle is in a running state. For example, until the determination unit 126 detects that the clutch state has changed, the rotational speed, the gear state, and the PTO state indicate the traveling state, and the traveling speed detected by the speed detecting unit is predetermined. If it is equal to or less than the threshold value, it may be determined that an abnormality has occurred in the speed detection means.

  Specifically, the determination unit 126 refers to the clutch switch flag stored in the storage unit 11 and recognizes that the clutch state has never changed from the off state to the on state or from the on state to the off state. In such a case, the clutch switch 4 may be out of order, and it is determined whether or not an abnormality has occurred without using the clutch information. More specifically, the determination unit 126 is in a state where the rotational speed is equal to or higher than the lower limit value of the rotational speed in the traveling state, the gear is engaged, and the PTO is not operating. When the traveling speed is equal to or lower than a threshold speed (for example, 5 km / h) stored in the storage unit 11, it is determined that an abnormality has occurred in the speed detecting means.

  After detecting that the clutch state has changed, the determination unit 126 indicates that the rotational speed, the gear state, the clutch state, and the PTO state indicate the traveling state, and the speed detected by the speed detecting means is equal to or less than a predetermined threshold value. If it is, it is determined that an abnormality has occurred in the speed detection means. For example, when the determination unit 126 refers to the clutch switch flag stored in the storage unit 11 and recognizes that the clutch state has changed from the off state to the on state, or from the on state to the off state, Since the switch 4 is considered to be operating normally, the presence or absence of an abnormality is determined using the clutch information. Specifically, the determination unit 126 is in a state where the rotational speed is equal to or higher than the lower limit rotational speed of the traveling state, the gear is engaged, the PTO is not operating, and the clutch is connected. However, when the traveling speed is equal to or lower than the threshold speed stored in the storage unit 11, it is determined that an abnormality has occurred in the speed detecting means.

[Flowchart showing determination processing procedure in abnormality detection apparatus 1]
FIG. 2 is a flowchart illustrating a procedure of determination processing executed by the determination unit 126.
The determination unit 126 first determines whether or not the engine speed is equal to or greater than the lower limit value of the engine speed in the running state (S11). When the engine speed is smaller than the lower limit value (No in S11), the determination unit 126 has no problem even if the traveling speed detected by the speed detection unit 125 is equal to or less than a predetermined threshold value, and does not proceed to S12. Repeat the process. If the engine speed is equal to or higher than the lower limit value (Yes in S11), determination unit 126 proceeds to S12.

  In S12, the determination unit 126 determines whether or not a gear is engaged based on the gear information acquired by the gear information acquisition unit 122. If the determination unit 126 determines that the gear is not engaged (No in S12), there is no problem even if the traveling speed detected by the speed detection unit 125 is equal to or less than a predetermined threshold value, so the process returns to S11 without proceeding to S13. . If determining unit 126 determines that the gear is engaged (Yes in S12), the process proceeds to S13.

  In S13, the determination unit 126 determines whether the PTO is operating based on the PTO information acquired by the PTO information acquisition unit 124. If the determination unit 126 determines that the PTO is in operation (Yes in S13), there is no problem even if the traveling speed detected by the speed detection unit 125 is equal to or less than a predetermined threshold value, so the process proceeds to S11 without proceeding to S14. Return. If the determination unit 126 determines that the PTO is not operating (No in S13), the determination unit 126 proceeds to S14.

  In S14, the determination unit 126 determines whether the traveling speed detected by the speed detection unit 125 is smaller than a predetermined threshold value. When the traveling speed is equal to or higher than the predetermined threshold (No in S14), the determining unit 126 returns to S11 without proceeding to S15 because the speed detecting means is considered to be operating normally. When the traveling speed is smaller than the predetermined threshold (Yes in S14), the determination unit 126 proceeds to S15 because the speed detection unit may be out of order.

  In S15, the determination unit 126 refers to the clutch switch flag stored in the storage unit 11. When the clutch switch flag indicates that the clutch state has changed in the past, the determination unit 126 acquires the clutch information from the clutch information acquisition unit 123 and determines whether or not the clutch is engaged (S16). ). If the determination unit 126 determines that the clutch is engaged (Yes in S16), the traveling speed detected by the speed detection unit 125 is smaller than the threshold value even though the traveling speed should be equal to or higher than the threshold value. From this, it is determined that an abnormality has occurred in the speed detection means (S17), and the determination result is output (S18). If the determination unit 126 determines in S16 that the clutch is disengaged (No in S16), the determination unit 126 determines that no abnormality has occurred in the speed detection unit and returns to S11.

In S15, when the clutch switch flag indicates that the clutch state has not changed in the past, the determination unit 126 may have a failure in the clutch switch 4, and based on the rotational speed and gear information. Thus, it is determined that an abnormality has occurred in the speed detecting means (S19).
Note that the order of the processing from S11 to S13 is arbitrary.

(Modification)
In the above description, the determination unit 126 uses the state of the clutch switch 4 to determine whether or not an abnormality has occurred in the speed detection means based on whether or not the clutch state has changed in the past. It demonstrated as what switches whether or not. The determination unit 126 switches whether to use the state of the neutral switch 3 to determine whether or not an abnormality has occurred in the speed detection means based on whether or not the gear state has changed in the past. Also good. Similarly, the determination unit 126 determines whether or not an abnormality has occurred in the speed detection means based on whether or not the PTO operation state or the parking brake state has changed in the past. It may be switched whether to use the state.

  Specifically, the determination unit 126 refers to the neutral switch flag stored in the storage unit 11, and the rotational speed, the clutch state, and the PTO state run until it is detected that the gear state has changed. It may be determined that an abnormality has occurred in the speed detecting means when the state is indicated and the traveling speed detected by the speed detecting means is equal to or less than a predetermined threshold. In addition, after detecting that the gear state has changed, the determination unit 126 indicates that the rotational speed, the gear state, the clutch state, and the PTO state indicate the traveling state, and the speed detected by the speed detecting means is a predetermined speed. If it is less than or equal to the threshold value, it may be determined that an abnormality has occurred in the speed detection means.

  In the above description, the determination unit 126 determines whether or not the vehicle is running based on the engine speed, the gear state, the clutch state, and the PTO state. However, the present invention is not limited to this. . The determination part 126 may determine whether it is a driving | running | working state based on some states among these various states.

[Effect in the first embodiment]
As described above, the determination unit 126 of the abnormality detection device 1 according to the first embodiment determines that the traveling state is based on the engine speed, the gear state, the clutch state, and the PTO state. Nevertheless, when the detected traveling speed is equal to or lower than the predetermined threshold, it is determined that an abnormality has occurred in the speed detecting means. By doing in this way, even if it can be determined that the vehicle is in the traveling state based on the gear state, the clutch state, and the engine speed, it is not in the traveling state when the PTO is operating. Therefore, it is possible to improve the determination accuracy of occurrence of abnormality in the speed detection means.

  Whether or not the determination unit 126 uses the state of the clutch switch 4 to determine whether or not an abnormality has occurred in the speed detection means based on whether or not the state of the clutch switch 4 has changed in the past. Switch between. In this way, when a failure has occurred in the clutch switch 4, the determination unit 126 makes an erroneous determination that no abnormality has occurred even though an abnormality has occurred in the speed detection means. Therefore, it is possible to improve abnormality detection accuracy and enhance safety.

<Second Embodiment>
The abnormality detection device 1 according to the first embodiment determines whether an abnormality has occurred in the speed detection means based on the engine speed, the gear state, the clutch state, and the PTO state. On the other hand, the abnormality detection device 1 according to the second embodiment is the first in that it determines whether an abnormality has occurred in the speed detection means based on the accelerator opening and the fuel injection amount. Different from the embodiment. The engine information acquisition unit 121 in the first embodiment acquires the rotation speed information indicating the rotation speed of the engine from the engine control unit 2, but the engine information acquisition unit 121 in the second embodiment indicates the accelerator opening. It differs from the engine information acquisition unit 121 in the first embodiment in that information and information indicating the fuel injection amount are acquired from the engine control unit 2.

  Further, the storage unit 11 in the second embodiment stores a fuel injection amount table in which the engine speed is associated with the lower limit value of the fuel injection amount when a running load is generated. . The determination unit 126 refers to the fuel injection amount table stored in the storage unit 11, and the load generated in the traveling state is longer than the time indicating that the accelerator opening is equal to or greater than a predetermined value and the vehicle is traveling. In spite of the occurrence, when the traveling speed detected by the speed detection unit 125 is equal to or less than the threshold value, it is determined that an abnormality has occurred in the speed detection means. Specifically, the determination unit 126 travels after starting the engine when the accelerator opening is equal to or greater than a predetermined value and equal to or greater than the lower limit amount corresponding to the load of the travel state corresponding to the engine speed. When the traveling speed detected by the speed detection unit 125 is equal to or lower than the threshold value even though it continues for a period longer than the time required to start the operation, it is determined that an abnormality has occurred in the speed detection means.

  Here, the determination unit 126 has a fuel injection amount that exceeds a lower limit value for a period of time equal to or greater than a predetermined value and a time period indicating that the vehicle is traveling, and a load generated in the traveling state is generated. If the condition is satisfied, the fact is stored in the storage unit 11. In this way, the determination unit 126 is based on information in the storage unit 11 that the condition has been satisfied in the past even if the accelerator pedal is released immediately after the above condition is satisfied. Thus, it can be determined that the vehicle is in a running state, and it can be detected that an abnormality has occurred in the speed detection means. For example, the determination unit 126 determines that the vehicle is in the traveling state when the above condition is repeatedly satisfied, such as when the accelerator pedal is repeatedly depressed at short time intervals in a period of a predetermined time or longer. be able to.

  The determination unit 126 is based on the PTO information acquired by the PTO information acquisition unit 124 in order to prevent erroneous detection that a load in the running state is generated due to the operation of the PTO even though the vehicle is stopped. It may be determined whether or not the vehicle is running. The determination unit 126 may determine that an abnormality has occurred in the speed detection means on condition that the PTO information indicates that the PTO is not operating. By doing in this way, when the traveling speed detected by the speed detection unit 125 is small even though the fuel injection amount is increased in order to operate the PTO, the determination unit 126 causes the speed detection unit to malfunction. It is possible to prevent erroneous determination that occurrence has occurred. In addition, the determination part 126 may determine whether it is a driving | running | working state based on the information which shows the state of a parking brake instead of using PTO information.

[Flowchart showing determination processing procedure in abnormality detection apparatus 1]
FIG. 3 is a flowchart illustrating a procedure of determination processing executed by the determination unit 126 in the abnormality detection device 1 according to the second embodiment.
First, the determination unit 126 determines whether or not the accelerator opening acquired by the engine information acquisition unit 121 is equal to or greater than a threshold corresponding to the traveling state (S21). When the accelerator opening is smaller than the threshold (No in S21), determination unit 126 determines that the vehicle is not in a traveling state, and repeats the process of S21 until the accelerator opening is equal to or greater than the threshold.

  When the determination unit 126 determines in S21 that the accelerator opening is equal to or greater than the threshold (Yes in S21), the fuel injection amount falls below the fuel injection amount corresponding to the engine speed in a period of a predetermined time or more. It is determined whether or not the amount is greater than or equal to the limit amount (S22). When the fuel injection amount is smaller than the lower limit amount (No in S22), determination unit 126 determines that the vehicle is not in a traveling state, and returns to S21.

  Subsequently, when the determination unit 126 determines that the fuel injection amount is equal to or greater than the lower limit amount during a predetermined time period (Yes in S22), whether or not the traveling speed detected by the speed detection unit 125 is smaller than the threshold value. Is determined (S23). If determining unit 126 determines that the traveling speed is equal to or higher than the threshold (No in S23), it determines that no abnormality has occurred in the speed detecting means, and returns to S21.

  If the determination unit 126 determines that the traveling speed detected by the speed detection unit 125 is smaller than the threshold (Yes in S23), the determination unit 126 determines whether or not the PTO is operating (S24). If the determination unit 126 determines that the PTO is operating (Yes in S24), the determination unit 126 determines that it is not in the traveling state, and returns to S21. If the determination unit 126 determines that the PTO is not operating (No in S24), the traveling speed detected by the speed detection unit 125 is smaller than the threshold value in spite of the traveling state. It is determined that an abnormality has occurred (S25), and the determination result is output (S26).

  Note that the determination unit 126 may continuously perform the processes of S21 and S22 and the processes of S11 to S13 illustrated in FIG. Further, the determination unit 126 executes the processes of S21 and S22 and the processes of S11 to S13 in parallel, and determines whether or not an abnormality has occurred in the speed detection means based on the results of both processes. May be.

[Effects of Second Embodiment]
As described above, the abnormality detection device 1 according to the second embodiment determines whether or not the vehicle is in the traveling state based on the accelerator opening and the fuel injection amount, and determines that the vehicle is in the traveling state. First, when the traveling speed detected by the speed detecting unit 125 is smaller than the threshold, it is determined that an abnormality has occurred in the speed detecting means. By doing in this way, even if the neutral switch 3 or the clutch switch 4 is out of order, the abnormality of the speed detecting means can be detected correctly.

  Further, the abnormality detection device 1 satisfies the condition that the accelerator opening is equal to or greater than a predetermined value and the fuel injection amount is equal to or greater than a lower limit amount corresponding to a load in a traveling state corresponding to the engine speed. Is stored in the storage unit 11. By doing in this way, the abnormality detection apparatus 1 can correctly determine whether or not the vehicle is in the traveling state even when the accelerator pedal is released in a short time after the accelerator pedal is depressed.

  Moreover, the abnormality detection apparatus 1 can also determine whether it is a driving | running | working state further based on the operation state of PTO. By doing in this way, the abnormality detection apparatus 1 can prevent erroneous determination that the vehicle is in the traveling state when the fuel injection amount is increased by operating the PTO while the vehicle is stopped.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Abnormality detection apparatus 2 Engine control unit 3 Neutral switch 4 Clutch switch 5 PTO switch 6 Vehicle speed sensor 11 Memory | storage part 12 Control part 121 Engine information acquisition part 122 Gear information acquisition part 123 Clutch information acquisition part 124 PTO information acquisition part 125 Speed detection part 126 judgment part

Claims (4)

Engine information acquisition means for acquiring rotational speed information indicating the rotational speed of the engine;
Gear information acquisition means for acquiring gear information indicating a gear state;
Clutch information acquisition means for acquiring clutch information indicating a clutch state;
PTO information acquisition means for acquiring PTO information indicating the operating state of the PTO, which is a device for extracting the power of the engine;
Speed detecting means for detecting the traveling speed of the vehicle;
The rotational speed, the gear state, the clutch state, and the operating state of the PTO indicate a traveling state in which the vehicle is traveling, and the traveling speed detected by the speed detecting means is less than a predetermined threshold value. A determination means for determining that an abnormality has occurred in the speed detection means in a case;
An abnormality detection apparatus comprising: Until the determination means detects that the clutch state has changed, the rotational speed, the gear state, and the operating state of the PTO indicate a traveling state, and the traveling detected by the speed detecting means When the speed is equal to or lower than a predetermined threshold value, it is determined that an abnormality has occurred in the speed detection means, and after detecting that the clutch state has changed, the rotational speed, the gear state, the clutch state, and the PTO When the operating state indicates a traveling state and the traveling speed detected by the speed detecting unit is equal to or less than a predetermined threshold, it is determined that an abnormality has occurred in the speed detecting unit,
The abnormality detection device according to claim 1. The engine information acquisition means further acquires an accelerator opening and a fuel injection amount,
The speed detecting means, although the accelerator opening is not less than a predetermined value and the fuel injection amount is not less than the lower limit amount of the fuel injection amount in the running state corresponding to the rotational speed. When the detected traveling speed is equal to or lower than a predetermined threshold, it is determined that an abnormality has occurred in the speed detecting means.
The abnormality detection device according to claim 1 or 2. The determination means stores that the condition that the accelerator opening is equal to or larger than a predetermined value and the fuel injection amount is equal to or larger than a lower limit amount corresponding to a load in a traveling state corresponding to the rotation speed is satisfied. It is memorized in the part,
The abnormality detection device according to claim 3.

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